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Finding the Fourth Proportional to 476.78, 657.79 and 290.21

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Solution

The fourth proportional to 476.78, 657.79 and 290.21 is: 400.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    476.78 : 657.79 = 290.21 : x
  2. Step 2: Convert to fraction form
    476.78/657.79 = 290.21/x
  3. Step 3: Cross multiply
    476.78x = 657.79 × 290.21
  4. Step 4: Simplify right side
    476.78x = 190,897.24
  5. Step 5: Solve for x
    x = 190,897.24/476.78
  6. Step 6: Final answer
    x = 400.39

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.